Bobbin



Aug. 22, 1939. F.E..DOUGLAS 2,170,773

BOBBIN Filed Apfil 4, 1939 INVENTOR.

\ ATTORNEY.

F ZEDE/c E DOUGLAS.

Patented Aug. 22, 1939 UNITED STATES BOBBIN Fredric E. Douglas, Hopedale, Mass, assignor to Draper Corporation, Hopedale, Mass, a corporation of Maine Application April 4, 1939, Serial No. 265,954 3 Claims. 01. 242 120) The present invention. pertains to bobbins of the type used in automatic bobbin, changing looms.

Bobbins of the type to which my invention applies comprise a barrel portion on which filling thread is wound, and a butt portion having a plurality of holding rings adapted to seat in notches in the spring jaws of a loom shuttle Such bobbins are made of non-metallic material, usually wood. As usually constructed prior to the present invention, the holding rings were made of round steel wire and were split and seated in individual half-round circumferential grooves in the bobbin butt.

The aforesaid prior construction is subject to several substantial disadvantages, including" the difiiculty of obtaining and keeping uniform spacing between the individual rings seated in individual grooves. Also, the rings would contract in service, often to difierent degrees so that they would not properly cooperate with the shuttle spring jaws. This contraction of the rings is, to a large extent, the result of insufiicient bearing area between the rings and the wood of the bobbin butt. Other disadvantages of the prior conistruction are well known in the art and need not be recited herein.

A principal object of the present invention is do provide a bobbin for automatic bobbin changing looms which bobbin shall comprise a barrel portion and non-metallic butt portion as aforesaid, with a plurality of steel holding rings mounted on the butt portion, which rings in cross-section shall have a relatively wide base providing a substantially increased bearing area in contact with the bobbin butt, and a relatively narrow top adapted to fit the notches in the usual shuttle spring jaws, whereby such bobbin shall not have the aforesaid disadvantages of the bobbins of the usual prior construction.

The foregoing and other objects of the invention are accomplished in the construction illustrated on the accompanying drawing, of which:

Fig. 1 is a fragmentary plan view of a. loom shuttle having the preferred embodiment of my improved bobbin therein;

Fig. 2 is a view of said bobbin and the shuttle spring of said shuttle, in cross-section as indicated by line 2 of Fi Fig. 3 is a view of said bobbin to a larger scale and. with part of the bobbin rings broken away; and

Fig. 4 is a perspective view of one of my improved bobbin rings.

The shuttle shown on the drawing is of the usual type for use in automatic bobbin changing looms. Such shuttle includes a body I having a cavity 2 therein for receiving a bobbin 3, and spring jaws 4 for detachably holding the bobbin in the cavity 2. The bobbin comprises a barrel portion 5 and a butt portion 6 having rings thereon as hereinafter described in detail. The opposed spring jaws grip these rings to hold the bobbin in place. The usual loom mechanism, not shown, ejects the bobbin from the shuttle by driving a fresh bobbin down onto the bobbin in the shuttle, the fresh bobbin being then held by the spring jaws 4, as is well known in the art.

Weaving conditions require that the bobbin be firmly held in place in the shuttle and not allowed to move or wobble. Accordingly, the spring jaws 4 are commonly provided with spaced notches I in which the aforesaid rings on the bobbin butt are firmly seated. The bobbin is thereby firmly held, if the rings are properly spaced and firmly seated and-held on the bobbin butt. The rings are, of course, properly tight when the bobbin is new, but the striking of the rings on one bobbin against the rings on the other bobbin during transfer tends to crush the wood of the bobbin and thereby loosen the rings. Also, the varying conditions of humidity to which the bobbin is subjected tends to loosen the rings, particularly as previously constructed.

In accordance with the present invention, the bobbin butt 6 is provided with steel rings 8 of a novel construction, and seated on the bobbin butt in a novel manner, whereby the rings are more firmly retained in place and loosening of the rings is substantially eliminated. As shown, instead of providing separate grooves in the bobbin butt as heretofore, I provide one wide groove 9 which may be relatively shallow. The rings 8 are split as shown at I0 and are seated side by side in the groove 9.

The construction of the rings 8 is novel in that the rings are of an entirely new shape in crosssection. As shown, this cross-section is roughly triangular, the ring having a relatively wide base I I, tapered sides I2 and a rounded relatively narrow top 13. The width of the base I I is such that the total Width of the three rings is equal to the width of the groove 9. The tapering of the rings at I2 results in the tops I3 thereof being spaced apart the proper distance to lit the usual notches I in the shuttle spring jaws 4. The diameter of the rings; is such that they grip the butt portion tightly.

The use of a single wide and relatively shallow groove 9, instead of three spaced half-round grooves as heretofore, is of advantage in that the single groove is easier to make accurately, and does not cut so far through the wood of the bobbin butt. The three rings which fill the groove, as described, support and position each other so that it is practically impossible for them to move out of alignment or become improperly spaced. Even more important is the fact that the greatly increased bearing area H prevents crushing or mutilation of the wood of the bobbin and thus insures that the rings will grip the bobbin butt tightly throughout the useful life of the bobbin. It is also noted that the rings disclosed have sufiicient body that they will retain their shape better in service.

Having fully disclosed the preferred embodiment of my invention, I claim:

1. A bobbin for automatic bobbin changing looms, said bobbin comprising a barrel portion, a non-metallic butt portion having a single wide circumferential groove therein, and a plurality of steel holding rings seated side by side in said single groove, each of said rings in cross-section having a relatively wide base providing a substantial bearing area engaging the bottom of said groove and a relatively narrow top adapted to fit the holding notches of the usual shuttle spring jaws, the total width of the base portions of said rings being equal to the width of said groove.

2. A bobbin for automatic bobbinv changing looms, said bobbin comprising a barrel portion, a non-metallic butt portion having a single wide circumferential groove therein, and a plurality of steel holding rings seated side by side in said single groove, said rings being split and being of such a diameter that they grip said butt portion tightly, each of said rings in cross-section having a relatively wide, substantially flat base in contact with the bottom of said groove and a relatively narrow rounded top adapted to fit the holding notches of the usual shuttle spring jaws.

3. A bobbin for automatic bobbin changing looms, said bobbin comprising barrel and butt portions made of Wood, said butt portion having a single wide circumferential groove therein, and a plurality of steel holding rings seated side by side in said single groove and substantially filling the same, said rings being split and being of such a diameter that they grip said butt portion tightly, each of said rings being substantially triangular in cross-section with the base thereof engaging the bottom of said groove and the apex thereof rounded to fit the holding notches of the usual shuttle spring jaws.

FREDRIIC E. DOUGLAS. 

